Skin blood flow is the target of thermoregulatory reflexes (skin and internal temperatures). This circulation is also the target of a number of non-thermal reflexes, including baroreceptor reflexes and the reflexes associated with exercise. The major aim of this series of studies is to establish whether and to what extent the non-thermal reflexes modify the cutaneous vascular responses to thermoregulatory reflexes. Major attention is to be focussed on exercise and exercise with elevated skin temperature (water-perfused suits). Exercise represents a non-thermal reflex drive with a built-in thermal drive (rising internal temperature). Specific questions addressed will be: (a) can exercise at high levels significantly modify the cutaneous vascular response to rising internal temperature? (b) can heat stress modify or abolish responses to the initiation of exercise? (c) Do responses to isometric and dynamic exercise differ substantially? (c) does sweat rate respond to non-thermal reflexes?